I can't believe the flame wars that go on over this. At Anime-Forums, they had a huge flame Syaoran thread where people were taking alot of low shots at Syaoran (some were pretty funny, I must admit), but anyway, there was this huge philosophical discussion of how Syaoran was just using Sakura the whole time, and how it's a message to girls everywhere to avoid predators or something like that.....
Of course, this is all fueled by Sakura+Tomoyo supporters, which to me, is the worst anime couple ever. I mean, it would completely butcher Tomoyo's character if they ended up together. Tomoyo loved Sakura, so she wanted Sakura to be happy NOT to be with her. It would really diminish the power of Tomoyo's love if they ended up together.
As for S+S, it's really one of the most popular anime couples in existence. I've never seen a bigger fanbase for a single couple like that, and there is no denying it is a canon in CCS and Tsubasa from the start. They are an extremely compatible couple, and their relationship is very realistic from my personal experience with relationships. They are extremely similar in alot of ways yet completely opposite in others, and they really complement each other quite nicely. CLAMP definately wasn't timid about making them a canon, and that's why CLAMP is so awesome. They always get the coupling right unlike most other animes.